0 to (cause something or someone to) have difficulty imagining or understanding something: --
He boggled at the suggestion.
It boggles the imagination, doesn't it?
1 to have difficulty imagining or accepting something as true or possible, or to give the mind such difficulty: --
The mind boggles at the sort of figure that would be discussed today.
One's imagination boggles at the difficulties which must beset the poor man in knowing what he can do and what he cannot do.
The mind boggles to think of those who loved him who were so freely thrown overboard.
Frankly, my mind boggles at the number of computations that there could be in having different codes applying to different parts of subsection (2).
I believe that it would open up a veritable minefield, and the imagination boggles at the muddle, confusion and possible danger that would ensue.
The mind boggles at the degree of humiliation to which children may be subjected by their fellows if they were carrying electronic tags.
The ordinary small property-owner is simply boggled when he looks at the form.
The mind boggles, but the nation is warned.